Control mechanism for drilling machines



CONTROL MECHANISM FOR DRILLING MACHINES Filed April 14, 1945 3 Sheets-Shegn 1 INVENTOR. MW l-T CHURCH/LL April 1, 1947. 1. F. CHURCHILL 7 2,413,220

CQNTROL MECHANISM FOR DRILLING MACHINES Filed April 14, 1945 5 Sheets-Sheet 2 IN V EN TOR.

@MfW

A 770A Vii 6 April 1947- I. F. CHURCHILL CONTROL MECHANISM FOR DRILLING MACHI NES Filed April 14, 1945 I5 Sheets-Sheet 5 *M m L. QM WHIIIIAUE Mb v a INVENTOR. 1mm E CHURCH/LL Rh QQ NW Arman Em;

Patented Apr. 1, 1947 OFFIC Common MECHANISM FOR DRILLING ,MA ES,

m R t w wea emil ta i n Am 14, 59!

4. east -Ur e? This invention relates to power drilling ma;- chines or drill'p resslfs and has for its ob ect a simple, readily applied control mechanism there: for for withdrawing the' lill when thefdrili an: counters undue resistance that 'would or might break it were the drilling operation "continued, as when the bore fills up'with chips, withdraws the drill and again automatically feeds it after h or s b n a ed b t by t e w t rawa of the drill, combined with a mechanism t rei: er e 9 W t draw h G i LlWI' e dr l h s bored 'to a predetermined depth and stop the il l q e ing a th ndlbf is' iith and to se a ma a I QIi Q b whi h the .dti operation is initiated to again start the f ding when t e m nua en re s bp iat gi t9 ii ili Th in enti r h r has iQr its 9 9 912 a 9011: trol mechanism which'ernbodies 'a latch common to h ee i g m hani m a t inel an lsm which determines 'thedepth of the hole being bored, Whibh la b is t ed by t e throwin out s s n v r 'aq'eluit h the Spindl rotating mechanism, when the drill encounters undue s i and b d pth d 't tm nins ch m w o? he'h e bqie a iven depth. k

The invention consists in the novel f e atures and in the combinationsand constructionshereinafter set forth and claimed.

In describingthis invention, reii'erence is had to the accompanying drawings in which like characters designate corresponding parts in' all the views.

Figure 1 is a side elevation of a ,drill press or drilling operatipnfis mc thgmnza matte does nritirpeatj until" a manuafcontrolniembr by which the fnitiated'isfagain operated; 1$ Wheh ar'iiew hole is tobe bored." '1' de na est el stand rd; lithe Q erhangins head, and 3 the table; Iqi a'drill press; 4 use; Hates the axially mo'tableaiid rptating jspindle h ingi'a chiickfg for; the tboliorfdr lli The. he n 'sm for s uttin means httws il" i ibtmbt r' a d the; Sp t dl,'e "Ijhi's motion transmitting i s ttfl pie ead 5 l h tah e i Q 81 it I Wh Sh -FF a $113? iti e' e ove aid'asain t suitabl ream; p in Z ai c1 belts L !i,' tween th nifit r haft in the. d iv a t e tinnii a d be we n he d ven shaft se tic!!! a id hespini (11s, the e H' n "m Pre tiest Pa lets l6 on the "upper end of the driven shaft section! nd 1 h fu n r en oi' e s indl 4- Thebim se drilling machine having the feed and deptheop trol mechanisms applied thereto.

Figure 2 is an elevation looking to the right in Figure 1, parts being omitted.

Figure 3 is an elevation looking to; the left in Figure 1, parts being omitted.

Figures 4 and 5 are elevations of the ieed mechanism for the spindle, partly in section, Fi guregi showing the parts including the manual in their starting position, and Figure 5 when in their m ning position.

This invention comprises, generally, a latch operable both by the throwing'out of an overload clutch in the spindle rotating nnechanism, which clutch throws out when the drill encounters undue resistance, and also by a depth determining mech anism operating to throw out the latch when the hole is 'loored to a predetermined depth, which latch controls reverse control members. a Elvi o the Rev si le me er missile 9 the eril i ees as i to thehea'd '2'; While "the motor is ,7 ed iaws'ca lah eq ra sli i t nde -en overlo d. "The" motor fla'ndfthe 'shaft" sections 8 .9 a e. a ied a mete r br cke "l1. s j ufr fi when b i i siy th h m will s renal, 'g."

m m are as t drill spi dl eqmtr se e t ibll a q it. swim; m t: J i i' f ioi a d hi9 ten iiti a be w n" h iwif fil m m y QI tm i t ant h i fid 0 e fi '.ihi sin, a e 2 ;1 :11 9, 90- if Pbt Q- 'e' t tti t e m 18 i n r d it. new Z'twhmh s als a rev si' b i t T he u ee rb m mbe H, ih e-l in, mass gapeiataby themqvahlefmember or the reversib le nteqi 20 hen'it-is actuated in one direction; (as "when the member" is Der sited manual-lyto' shift the reversing meiiih V [9 for tliinot'o'r i8), to au'se the motor [8'to iie ini: many energized and bpe f itea'tdred m the idrill, and to inove ativlv to this reversing ineinih ei' [9 without operating'it when finove'd "inthe other li in l9 tim 9? tii ili v da in the" spindle it ,inelude an lec'tric mqtbr'ra a'mo Qri for the purposejof illustration only, is shown-as a;

spring 22 acting on a lever which operates the sh et I control member l9. This spring is, however, selfcontained Within the control member as is the spring 48 (Figure 4) a As the feeding and control mechanism is pnii- .15

matic or air-operated, the control motor 18 is shown as a reversible cylinder and piston motor. The motor 20 also is shown as a reciprocating or reversible cylinder and piston motor, and the control members If! and 2| and also a control member 23 for. the motor'20are shown as valves. "Ifhe motion transmitting means operated by thejmovableymember or piston 24 of the feed motor I8 is here shown as a rack 25 on the piston rod 26" and meshin with a pinion 21 on a sleeve 28mounted on a rotating shaft 29 supported by and extending laterally from the head 2. The shaft 29 has a pinion, not shown, within the head [meshing with a. rack on the spindle 4, as in any standard feed mechanism. The sleeve 23 is one section ofan overload clutch and has cam or." beveled jaws at its end, coacting with complementalijawson another axially movable sec-' tidn130 o'ri'the shaft 29, this section 30 being shiftable axiallyslightly against the action of a spring 3| under greater than normal torque or slight overload. v-Th,e control motor 20, as before stated is a cylinder and piston motor and its piston 32has its rod 33 provided with a for]; 34which coacts with a shoulder. 35 on a rod 36 extendin parallelto the piston rod 33. The fork'34 andshoulder 35 form, in a general sense, alone-way clutch. The rod .36 is part of the operating connections for'the reversing valve 19 andfi jhere shownias connected to a lever'3l pivoted at its angle'at 38and having its angular armJocated to press the stem 39 of the control valve-l9.against theiaction of the spring 22. Owing to. the oneewaylclutch device, the piston ing normally in position to exhaust air from the left end of the cylinder, when the piston 32 is moving to the right upon operation of the valve 2! from closed position (Figure 4) to open position (Figure 5), by the pulling of the manual I member to the right. As here shown, the reversing valve 23 is held in the position shown in Figures4- and 5 at the start of the feeding movenient ofthedrill, by a lateral arm 46 on the piston rod 26 of the feeding mechanism, the arm 46 ,pressing against the stem 41 of the valve 23. The

valve 23 is biased by a spring 48 to press the stem :,.4.'|;toward the arm 46 and to shift the valve when the arm 46 moves away from the valve stem 4'! at the start of the feeding-in movement of the piston 24 and its rod 26 to the left. The arm 46 also again resets or reverses the valve 23 when 32 iactuates the rod 136 only in one direction as 4 tolth'e left, and only when the manual member is operated or pulledout to open the valve 2 I.'

-40 designates 'a latch operated by the shiftable section II of the overload clutch l0 tFigure 2),

and alsoby the spindle feeding mechanism, whenthefhol'e has been drilled to a predetermined depth. .'-'Ihe latch is located to enter a notch 4| in the rod 36 when the rod is operated into positionshownflin Figure 5 from that shown in.

Figure 4,that;is, operated to the left by thepiston 32, upon thelpulling of the manual operating rod 45 to the right. The latch, as seen in Figure 2,

is a lever having one end located in the path of 1 a collar 42 on the shiftable section ll of the overload-clutch Ill. The action of the latch 46 wardly, it sets an additionalcontrol or reversing starting or cut-off position, so that'the piston24;

valve 23 for the'control motor 26, this valve be His shown as extendingthe piston 24 and its rod 26 return to the right after each latch releasing operation by the overload clutch sleeve II or by the depth determining mechanism. As the piston 24 shifts to the left, thearm 46 will move away'from the stem, letting the valve 23 shift to the left, so'that it Willassume a position wherein the air can exhaust from the right end of the cylinder bore of the control valve' zil and enter the left end past the'valve 2|, thus 'moving'the piston 32 to the right andmoving the fork 34 of the one-way clutch device away from thev collar 35 on the rod-36, so that the rod 36 is free to shift to the right under the action of the spring 22 when-- parallel to the spindle and carried by a laterally extending bracket 5| which moves vertically with the pindle 4, the nut bein located to come in contact with a stop 52 extending laterally fromthe head 2. r The nut orshoulder 49 may be adjusted a predetermined distance from the stop, this distance being dependent upon the depth of the hole to be bored. When the downward movement. of the drill is stoppedby the nut 49 engaging'the stop 42, the overload clutch section 3 fl.will shift axially slightly permitting additional movement of the feed mechanism relative to the drill spindle. 1 The depth "determining mechanism includes mechanism operated bythefeeding-in movement ofthe drill spindle or its motion transmitting means, as the piston rod 26, for tripping the latch 40, and thus permitting the valve l9 to reverse and permit the air to enter the left end of the cylinder l8. This depth determining mechanism includes an adjustable shoulder 53 on a sleeve 54 slidable on the control rod 36 and the arm 46' on the piston rod 23. The shoulder 53 constitutes an adjustable nut and a lock nut, and their;

adjusted position along the sleeve 54 determines the depth of the hole to be drilled by cutting out theffeed mechanism. The sleeve 54 has a shoulder 'or head'55 at its end for thrusting against a sleeve 51A on the rod 36, the sleevebeing slidable in the bracket 44; It is provided with a ofthe cylinder Idwithdraws the drill. The feedand the latch iii to permit the arm 57113 to pick up the shoulder 55 and return the rod 45 tothe left and the valve 2! toclosed position just ahead of the time the cam 51 trips the latch. The shoulder 53 and the nut is must be adjusted in accordance with the depth of the hole to be bored, so that the arm 45 engages the shoulder 53 approximately when the nut 49 engages the stop 52. The overload clutch section 30 (Figure 3) permits this continued movement of the piston rod 26 and arm d relatively to the stop spindle, so that the sleeve 54 can operate to shift the cam 51 and the rod 45 after the spindle is stopped from feeding axially. The positive stop mechanism 39, 5e, 55 may be omitted. Upon the releasing of the latch 4d, and hence the reversing of the valve 19, and the resetting of the manual control rod t5 in its position assumed when the valve H is closed, the machine is prevented from repeating its operation, when the hole has been bored to a predetermined depth To start the machine tobore another hole, the operator must again pull the red 45 to the rig t to open the valve 2!.

In operation, the shoulders .49, 53 having been set for the depth of the hole and with the parts in the position shown in Figure 4. and also the shoulder as on the sleeve 5d adjusted in accordance with theshoulder t9, the operatorpulls out or to the right the rod 45, this shifting the control valve 25 to open the intake port for the control member 2e, so that air will pass to the right hand side of the piston 32 and actuate the piston 32 to the left, causing the fork 34 on the piston rod 33 to pick up the shoulder 35 on the rod 36 and thus automatically operate the reversing valve 9 for the cylinder it. This permits air to enter the right end of the cylinder 18 and actuate the piston 24 to the left, which through the piston rod 25, rack and pinion 24 and 21, shaft 29 and overload clutch 28, 30, causes the drill spindle 4 to feed downwardly, During this movement, the arm 45 on the piston rod 25 moves away from the stem 41 of the spring biased valve 23 permitting this valve to reverse, so that the left hand end of the cylinder bore of the control member 20 is free to receive air and the right hand end is open to exhaust, and the piston 32 moves to the right, moving the shoulder 34 away from the collar 35. The latch 40 holds the rod 36 and the reversing valve l9 in their operated positions, the latch 60 having snapped into the notch il during the movement of the rod 36 to the left. Whenever the drill encounters undue resistance to its rotation, the latch 49 will be moved out of its notch 4!, permitting the valve [9 to reverse under the influence of the spring 22, thus reversing the piston 24, so that it moves to the right, and in so doing, withdraws the drill through the piston rod 26 and feed mechanism described. The overload clutch H] is selfresetting. When the piston rod 26 returns to the right, in which position the arm 46 again resets the valve 23, air will again enter the right hand end of the cylinder bore ef'the' valve motor 20' and move the valve piston 32 to the left, thus again reversing the valve Hi from the position shown in Figure 4 to that shown in Figure 5, so that the piston 21! will again move to the left, feeding the drill spindle '6 downwardly through the piston rod 26 and motion transmit-' ting means operated thereby. When the shoulders 49 of the stop mechanism stop the downward feeding of the drill spindle 4 by engaging the stop 52, the overload clutch 30 will slip or throw out slightly, and in so doing permit the arm' tt, which has been feeding continuously with the piston rod 26 to contact the shoulder 53 on the sleeve 54 and moves the shoulder 55 to successively shift the manual rod 45 and the cam 5! to trip the latch lii. The shifting of the manual rod it shifts the valve 2! to cut-off position, stopping the machine against repeated oper-' ation, until the rod 45 is again pulled outward to the right.

During the boring of the hole, the drill may be stopped several times by encountering undue resistance causing the throwing out of the overload clutch, and the drilling automatically resumed after each Withdrawal. When the hole is bored to a predetermined depth, owing to the ratcheting clutch 39, the drill may continue to rotate for a brief period to clean out the bottom of the hole and the chips before being withdrawn, while the clearance is being taken up between the cam 53 and the latch 40.

What I claim is:

1. In a control for drill presses having a drill spindle, power operated mechanism for rotating the drill spindle, feeding mechanism for the drill spindle including a reversible cylinder and -pis-' ton motor, a reversing control valve therefor having biasing means to shift it into position to cause the piston to move in one direction to withdraw the spindle, and a manual operating member for controlling the operation of the control valve against the biasing means to cause the feeding in of the spindle; the combination of a self-resetting overload clutch included in said spindle rotating mechanism, a latch operable to hold the reversing control valve in its position occupied when the drill spindle is being fed into the work, means operated by the shifting out of the overload clutch to release the latch, and means operated by the feeding-in mechanism for tripping the latch when the drill has bored to a predetermined depth, thereby permitting the reverse control valve to return to starting position under the influence of its biasing means and return the manual to its initial starting position.

2. In a control for drill presses having a drill spindle, power operated mechanism for rotating the drill spindle, feeding mechanism for the drill spindle including a reversible cylinder and piston motor, a reversing control valve therefor having biasing means to shift it into position to cause the piston to move in one direction to withdraw the spindle, and a manual operating member for controlling the operation of the control valve against the biasing means to cause the feeding in of the spindle; the combination of a self-resetting overload clutch included in said spindle rotating mechanism, a latch operable to hold the reversing control valve in its position occupied when the drill spindle is being fed into the work, means operated by the shifting out of the overload clutch to release the latch, power means controlled by the spindle feeding mechanism and by the manual control member when in its operated positionfor operating'the reversing valve against the biasing means, and means operated by the feeding in mechanism for tripping the latch when the drill spindle has been fed a predetermined distance and for returning the manual member from its manually operated position to its initial position.

'3. In a control for drill presses having a drill spindle, power operated mechanism for rotating the drill spindle, feeding mechanism for the drill spindle including a reversible cylinder and piston motor, a reversing control valve therefor havingbiasing means to shift it into position to cause the piston to move in one direction to withdraw the spindle, and a manual operating member for controlling the operation of the control valve against the biasing means to cause the feedin in of the spindle; the combination of a self-resetting overload clutch included in said spindle rotating mechanism, a latch operable to hold the reversing control valve in its position occupied when the drill spindle is being fed into the work, means operated by the shifting out of the overload clutch to release the latch, power means controlled by the spindle feeding mechanism and by the manual control member when in its operated position for operating the reversing valve against the biasing means, means operated by the feeding mechanism for tripping the latch when the drill spindle has been fed a predetermined distance and for returning the manual member from its manually operated position to its initial position, means for stopping the feeding in of the drill spindle when the hole has been bored to a predetermined depth, the feeding-in mechanism including a yielding joint permitting a portion of said mechanism to continue the feeding movement farther slightly when the drill spindle is stopped, and means operated by the additional feeding movement for tripping the latch and returning the manual'member from its manually operated position to its initial position.

4. In a control for drill presses, the combination with a drill press having a rotating spindle,

8 power motion transmitting means for rotating: thespindle including an overload clutch, spindle feeding mechanism including a reversible motor, motion transmitting means operatedthereby for feeding the spindle axially, and a re-- versing control member for the motor including a self-returnable shiftable part, a second reversi- V ble control motor, and means operated thereby for operating the control member for the first motor into one position against its self-return-- able means, a manual control member operable in one direction manually for initiating the operation of the second motor to operate the control member for the first motor in one direction against its self-returning means; of a latch operable to hold the control member for the first motor in the position in which it is operated by the second motor upon operation of the manual; control member, an automatically operable reversing control member for the second motor and means operated by the feeding mechanism during the feeding-in movement thereof to control the operation of the reverse control member of the second motor when the feeding movement of the spindle has been initiated and resetting the same when the feed mechanism returns to start- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,816,829 DeLeeuw Aug. 4, 1931 2,260,327

McKee Oct. 28,1941 

